1 /*
2 * pthread_rwlock_init.c
3 *
4 * Description:
5 * This translation unit implements read/write lock primitives.
6 *
7 * --------------------------------------------------------------------------
8 *
9 * Pthreads4w - POSIX Threads for Windows
10 * Copyright 1998 John E. Bossom
11 * Copyright 1999-2018, Pthreads4w contributors
12 *
13 * Homepage: https://sourceforge.net/projects/pthreads4w/
14 *
15 * The current list of contributors is contained
16 * in the file CONTRIBUTORS included with the source
17 * code distribution. The list can also be seen at the
18 * following World Wide Web location:
19 *
20 * https://sourceforge.net/p/pthreads4w/wiki/Contributors/
21 *
22 * Licensed under the Apache License, Version 2.0 (the "License");
23 * you may not use this file except in compliance with the License.
24 * You may obtain a copy of the License at
25 *
26 * http://www.apache.org/licenses/LICENSE-2.0
27 *
28 * Unless required by applicable law or agreed to in writing, software
29 * distributed under the License is distributed on an "AS IS" BASIS,
30 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
31 * See the License for the specific language governing permissions and
32 * limitations under the License.
33 */
34
35 #ifdef HAVE_CONFIG_H
36 # include <config.h>
37 #endif
38
39 #include <limits.h>
40
41 #include "pthread.h"
42 #include "implement.h"
43
44 int
pthread_rwlock_init(pthread_rwlock_t * rwlock,const pthread_rwlockattr_t * attr)45 pthread_rwlock_init (pthread_rwlock_t * rwlock,
46 const pthread_rwlockattr_t * attr)
47 {
48 int result;
49 pthread_rwlock_t rwl = 0;
50
51 if (rwlock == NULL)
52 {
53 return EINVAL;
54 }
55
56 if (attr != NULL && *attr != NULL)
57 {
58 result = EINVAL; /* Not supported */
59 goto DONE;
60 }
61
62 rwl = (pthread_rwlock_t) calloc (1, sizeof (*rwl));
63
64 if (rwl == NULL)
65 {
66 result = ENOMEM;
67 goto DONE;
68 }
69
70 rwl->nSharedAccessCount = 0;
71 rwl->nExclusiveAccessCount = 0;
72 rwl->nCompletedSharedAccessCount = 0;
73
74 result = pthread_mutex_init (&rwl->mtxExclusiveAccess, NULL);
75 if (result != 0)
76 {
77 goto FAIL0;
78 }
79
80 result = pthread_mutex_init (&rwl->mtxSharedAccessCompleted, NULL);
81 if (result != 0)
82 {
83 goto FAIL1;
84 }
85
86 result = pthread_cond_init (&rwl->cndSharedAccessCompleted, NULL);
87 if (result != 0)
88 {
89 goto FAIL2;
90 }
91
92 rwl->nMagic = __PTW32_RWLOCK_MAGIC;
93
94 result = 0;
95 goto DONE;
96
97 FAIL2:
98 (void) pthread_mutex_destroy (&(rwl->mtxSharedAccessCompleted));
99
100 FAIL1:
101 (void) pthread_mutex_destroy (&(rwl->mtxExclusiveAccess));
102
103 FAIL0:
104 (void) free (rwl);
105 rwl = NULL;
106
107 DONE:
108 *rwlock = rwl;
109
110 return result;
111 }
112